New to the forum and I am a new wrx owner. So the other day I was going from 1st gear to second with high rpms as I was shifting I got a back fire and whitish grey smoke and all of a sudden my car started to sound like an STI and rough idle with intermittent backfire. Under boost normal driving it runs fine with no hesitation. Cleaned maf with no avail. Car is also running very rich. Not a mechanic so I need help as soon as possible. Thank you.